Calligonum L.
Genus composed of more than 140 species, mostly typical of the Asian deserts, 4 reach North Africa, where they settle in different habitats in dunes and interdune depressions of the Sahara.
Bannour, M., Lachenmeier, D.W., Straub, I. et al. 2016. Evaluation of Calligonum azel Maire, a North African desert plant, for its nutritional potential as a sustainable food and feed. Food Research International 1(558-564).
Dhief, A., Gorai, M., Aschi-Smiti, S. and Neffati, M. 2009. Comparative phenological and water potential patterns of three Calligonum species in the eastern Great Erg of Tunisia. Flora-Morphology, Distribution, Functional Ecology of Plants 204(8): 581-592.
Dhief, A.,Abdellaoui, R., Tarhouni, M., Belgacem, A. O., Smiti, S. A. and Neffati, M. 2011. Root and aboveground growth of rhizotron-grown seedlings of three Tunisian desert Calligonum species under water deficit. Can. J. Soil Sci. 91(15-27).
Gouja, H., Garnatje, T., Hidalgo, O., Neffati, M., Raies, A. & Garcia, S. 2014. Physical mapping of ribosomal DNA and genome size in diploid and polyploid North African Calligonum species (Polygonaceae). Plant Syst Evol.
Key to species
1 Fruits with few hairs, therefore their surface can be clearly seen, ending in a terminal tuft Calligonum calvescens
1 Fruits so densely covered in hairs that their surface cannot be seen, giving it the appearance of a woolly sphere, ovoid, 15-20 mm in diameter 2
2 Fruit cross section in a cross, in which each end has 2rows of hairs. Shrub 1-2 m in height, highly branched, without a main trunkand young branches grey Calligonum polygonoides
2 Shrub 2-3 m, with branches arising from a trunk sometimes partially buried in the sand. Old branches with whitish, fissured bark. Perianth parts with a green thickening on the dorsal side, yellowish anthers. Fruit hairs long, 8-10 mm, fused at the base into a membrane 3
3 Shrub 2-3 m, with branches arising from a trunk sometimes partially buried in the sand. Old branches with whitish, fissured bark. Perianth parts with a green thickening on the dorsal side, yellowish anthers. Fruit hairs long, 8-10 mm, fused at the base in Calligonum azel
3 Trees up to 10 m in height. Old branches with yellow-orange bark, slightly or not fissured. Perianth parts with a reddish thickening on the dorsal side, white anthers. Fruit hairs very long, 15-20 mm, free to the base Calligonum arich
Updated by: F. Alcaraz.